org.aksw.sparqlify.core.algorithms

Class ExprEvaluatorSql

java.lang.Object

org.aksw.sparqlify.core.algorithms.ExprEvaluatorSql

public class ExprEvaluatorSql
extends Object

Constructor Summary

Constructors

Constructor and Description
ExprEvaluatorSql(TypeSystem datatypeSystem, FunctionRegistrySql sqlFunctionRegistry)

Method Summary

Methods

Modifier and Type	Method and Description
SqlExpr	eval(SqlExpr expr, Map<String,XClass> typeMap) Some important fact: We only derive datatypes during evaluation.
static boolean	isConstantArgsOnly(SqlExprFunction fn)
static boolean	isConstantsOnly(Iterable<SqlExpr> exprs)
List<SqlExpr>	transform(Iterable<SqlExpr> exprs, Map<String,XClass> typeMap)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ExprEvaluatorSql

public ExprEvaluatorSql(TypeSystem datatypeSystem,
                FunctionRegistrySql sqlFunctionRegistry)

Method Detail

transform

public List<SqlExpr> transform(Iterable<SqlExpr> exprs,
                      Map<String,XClass> typeMap)

eval

public SqlExpr eval(SqlExpr expr,
           Map<String,XClass> typeMap)

Some important fact: We only derive datatypes during evaluation. Initially, we have variable definitions which include SPARQL expression with column references, but there is no type information included. And since these expressions will be transformed anyway, there is no point in prior assignment of datatypes. Just condider the concat(... ?int) = concat(... ?name): Eventually, this will be transformed into .... ?int = ... ?name, and only then we will discover a potential type error. FIXME: Ups, type errors in equals-concat expressions are evaluated to "false" rather than "type-error".

Parameters:

expr -

typeMap -

Returns:

isConstantsOnly

public static boolean isConstantsOnly(Iterable<SqlExpr> exprs)

isConstantArgsOnly

public static boolean isConstantArgsOnly(SqlExprFunction fn)